Yaskawa G7 Drive - Manual (Page 384)

Protective and Diagnostic Functions
7-
3
UV1
DC Bus
Undervolt
Main Circuit Undervoltage
The main circuit DC voltage is below
the Undervoltage Detection Level
(L2-05).
200-240 V class: Approx. 190 V
380-380 V class: Approx. 380 V
• An open-phase occurred with the
input power supply.
• A momentary power loss occurred.
• The wiring terminals for the input
power supply are loose.
• The voltage fluctuations in the input
power supply are too large.
Reset the fault after correcting its
cause.
UV2
CTL PS
Undervolt
Control Power Fault
The control power supply voltage
dropped.
-
• Try turning the power supply
off and on.
• Replace the Drive if the fault
continues to occur.
UV3
MC
Answer-
back
Inrush Prevention Circuit Fault
A fault occurred in the surge preven-
tion circuit.
-
• Try turning the power supply
off and on.
• Replace the Drive if the fault
continues to occur.
PF
Input Pha
Loss
Main Circuit Voltage Fault
The main circuit DC voltage oscillates
unusually (not when regenerating).
This fault is detected when L8-05 is
set to “Enabled.”
• An open-phase occurred in the input
power supply.
• A momentary power loss occurred.
• The wiring terminals for the input
power supply are loose.
• The voltage fluctuations in the input
power supply are too large.
• The voltage balance between phases
is bad.
Reset the fault after correcting its
cause.
LF
Output Pha
Loss
Output Open-phase
An open-phase occurred at the Drive
output.
This fault is detected when L8-07 is
set to “Enabled.”
• There is a broken wire in the output
cable.
• There is a broken wire in the motor
winding.
• The output terminals are loose.
Reset the fault after correcting its
cause.
The motor being used has a capacity
less than 5% of the Drive's maximum
motor capacity.
Check the motor and Drive capac-
ity.
OH
(OH1)
Heatsnk
Overtemp
(Heatsnk
MAX
Temp)
Cooling Fin Overheating
The temperature of the Drive's cooling
fins exceeded the setting in L8-02 or
105
°C.
The ambient temperature is too high. Install a cooling unit.
There is a heat source nearby. Remove the heat source.
The Drive's cooling fan has stopped.
Replace the cooling fan. (Contact
our sales representative.)
Drive's Cooling Fan Stopped
(18.5 kW or higher)
The Drive's cooling fan has stopped.
OH3
Motor
Overheat 1
Motor Overheating Alarm
The Drive will stop or will continue to
operate according to the setting of L1-
03.
The motor has overheated.
Check the size of the load and the
length of the acceleration, deceler-
ation, and cycle times.
Check the V/f characteristics.
Check the Motor Rated Current
(E2-01).
Table 7.1 Fault Displays and Processing (Continued)
Display Meaning Probable Causes Corrective Actions